Re: it seems my Gnuplot 4.0 didn't read my ~/.Xdefaults

[Ethan A M. <merritt@u.washington.edu>]

I think you may misunderstand how x11 works.

(1)
gnuplot (or any other x11 application) does not read the .Xdefaults
file by itself.   Instead, the x11 server reads the file when you
begin a new X-session, and applies the values in finds there to
answer queries from any applications (like gnuplot) that run later.

So editing the .Xdefaults has no automatic effect until the
next x-session.  You can force an update of the x-session values
by typing:
	xrdb -merge < ~/.Xdefaults

Even that, however, will not necessarily affect programs that
are already running. 

(2)
Setting a value for some particular X resource can only have
an effect if a corresponding application actually asks for that
value by name.  gnuplot does have a list of X resource values
that it asks for, but your "gnuplot*line30Width", for instance,
is not one of them.

-- 
Ethan A Merritt
Biomolecular Structure Center
University of Washington, Seattle 98195-7742